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<br /> <br /> <br />PAGE 55 <br /> <br />Stormwater Sub-Element <br />GOP Number GOP Language Recommended Action Comments/Rationale <br />Goal <br />Indian River County shall provide and maintain a drainage system which reduces the risk of property damage and <br />inconvenience from long term flooding, promotes stormwater recharge of the shallow aquifer, reduces stormwater <br />pollutant loading of the Indian River Lagoon and receiving waters and provides proper floodplain management. <br />Revise <br />Recommend: Indian River County shall provide and maintain an efficient <br />and effective stormwater management system which, to the maximum <br />extent practical, provides proper floodplain management; reduces risk <br />of property damage and promotes personal safety; promotes <br />stormwater recharge of the shallow aquifer; minimizes erosion and <br />water quality degradation; and reduces stormwater pollutant loading of <br />the Indian River Lagoon and receiving waters. <br />Objective 1 By 2030, all existing and new development in the unincorporated section of Indian River County will be protected from <br />flooding from a 25 year/24-hour storm event. Revise <br />Recommend: To the maximum extent practical where attainable, by <br />2030, the County shall actively manage a floodplain program to <br />minimize flood risk for existing development within the unincorporated <br />section of Indian River County. New developments will continue to <br />meet current or more stringent regulations as may be passed from time <br />to time. <br />Policy 1.1: <br />The county hereby adopts the following level-of-service standard for all new drainage systems within the <br />unincorporated county: New development requiring major site plan approval or subdivision platting shall construct a <br />drainage system capable of mitigating <br />the impacts of a 25 year/24 hour design rainfall event using the Natural Resource Conservation Service (NRCS) Type 2 <br />modified rainfall curves. Post development runoff shall not exceed pre-development runoff unless a maximum <br />discharge rate has been adopted for the applicable drainage basin and the discharge does not exceed that rate. If a <br />maximum discharge rate has not been adopted for the applicable basin, post development discharge may not exceed <br />pre-development discharge. <br />Revise <br />New development requiring major site plan approval or subdivision <br />platting where impervious area exceeds 5,000 square feet, shall <br />construct a drainage system capable of mitigating the impacts caused <br />by discharge of a 25 year/24 hour design rainfall event as determined by <br />SJRWMD published rainfall quantities using the Natural Resource <br />Conservation Service Type 2 Florida modified rainfall curves (FLMOD). In <br />cases where downstream flooding has occurred the 100 year/24 hour <br />design rainfall event shall be considered. <br />Policy 1.15: <br />The county hereby adopts the following level-of-service standard for all new drainage systems within the <br />unincorporated county: New development requiring major site plan approval or subdivision platting shall construct a <br />drainage system capable of mitigating <br />the impacts of a 25 year/24 hour design rainfall event using the Natural Resource Conservation Service (NRCS) Type 2 <br />modified rainfall curves. Post development runoff shall not exceed pre-development runoff unless a maximum <br />discharge rate has been adopted for the applicable drainage basin and the discharge does not exceed that rate. If a <br />maximum discharge rate has not been adopted for the applicable basin, post development discharge may not exceed <br />pre-development discharge. <br />No Change <br />Policy 1.2: <br />The finished floor elevation of any new building constructed within a SFHA}, as designated on the most current Flood <br />Insurance Rate Maps (FIRMs) of the National Flood Insurance Program (NFIP), shall be subject to the following <br />requirements: <br /> ~ "AE" zone - structures must be elevated a minimum of six ( 6) inches above the base flood level; "A" zone - <br />structures must be elevated a minimum of 18 inches above the crown of the road or at the elevation required by the <br />DHRS, whichever is higher; if no base flood data are available, the structure must be elevated at least three (3) feet <br />above the highest natural elevation or the ground surface prior to construction next to the proposed walls of the <br />structure; <br /> ~ "VE" zone- structures must be elevated so that the bottom of the lowest horizontal structural member of the <br />lowest floor is elevated one-half (1/2) foot or more above the base flood level. <br />Revise <br />Consider: All new buildings shall be above the 100 Year storm event <br />along with any required appropriate freeboard protection. Elevations <br />shall be as defined by Flood Insurance Rate Maps, National Flood <br />Insurance Program requirements, engineering studies and as defined in <br />the County Stormwater Management and Flood Protection ordinance <br />and codes.